APA (7th ed.) Zitazioa
Collins & Univesity of Birmingham. (1990). Collins COBUILD English grammar. Collins.
Chicago Style (17th ed.) Zitazioa
Collins & Univesity of Birmingham. Collins COBUILD English Grammar. London: Collins, 1990.
MLA (9th ed.) Zitazioa
Collins & Univesity of Birmingham. Collins COBUILD English Grammar. Collins, 1990.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.